Endothelial precursor dysfunction in development of diabetic acellular capillary

糖尿病脱细胞毛细血管发育中的内皮前体功能障碍

基本信息

批准号：
8009929
负责人：
Maria Bartolomeo Grant
金额：
$ 17.93万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-09-30 至 2012-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8009929
关键词：
Acetylcholine Actins Acute Adherence Adult Advanced Glycosylation End Products Affect Age Animal Model Animals Area Arts Biochemical Biological Biological Assay Biological Availability Blindness Blood Vessels Blood capillaries Blood flow Bradykinin Brain Hypoxia-Ischemia CD34 gene Cell Death Cell-Matrix Junction Cells Chronic Collagen Type IV Confocal Microscopy Cyclic GMP Cyclic GMP-Dependent Protein Kinases Cytokine Receptors Cytoskeleton DNA Sequence Rearrangement Data Defect Development Diabetes Mellitus Diabetic Retinopathy Diabetic mouse Down-Regulation Dropout Endothelial Cells Endothelium Environment Epithelial Equilibrium Fluorescence Microscopy Functional disorder Generations Grant Growth Factor Hematopoietic Home environment Human Hypoxia Image In Vitro Individual Injection of therapeutic agent Injury Ischemia Lead Lesion Maintenance Mediator of activation protein Membrane Microfilaments Migration Assay Modeling Molecular Molecular Motors Motor Mutate Nature Nitric Oxide Nitric Oxide Donors Nitric Oxide Signaling Pathway Nitric Oxide Synthase Nude Mice PECAM1 gene Pathway interactions Patients Pericytes Phosphorylation Site Pigments Play Population Process Property Protein Isoforms Proteins Regulation Reperfusion Injury Research Personnel Retina Retinal Reverse Transcriptase Polymerase Chain Reaction Rodent Rodent Model Role Secondary to Signal Transduction Staining method Stains Streptozocin Stromal Cell-Derived Factor 1 Substance P Techniques Testing Time Transfection Vascular Endothelial Growth Factor Receptor Vascular Endothelial Growth Factors Western World Work base capillary cell motility cell type diabetic diabetic patient glycation glycosylated fibronectin injured matrigel migration non-diabetic novel pigment epithelium-derived factor polymerization precursor cell programs proliferative diabetic retinopathy repaired response retinal ischemia stem tool vasodilator-stimulated phosphoprotein

项目摘要

DESCRIPTION (provided by applicant): Diabetic retinopathy (DR) is a primary cause of blindness of working age adults in the Western world. Early pericyte dropout and endothelial cell death result in the formation of acellular capillaries, which cause retinal hypoxia and ischemia and are important contributors to DR development. We have shown have that hematopoietic stem and endothelial precursor cells (EPC) readily home to the retina in healthy animals, but that EPC of diabetic animal and humans have a migratory defect. Our preliminary studies demonstrate that EPC dysfunction may provide a novel mechanism for development of acellular capillaries in diabetic retinopathy. Our data suggest that within EPCs, nitric oxide (NO) plays a key role in regulating the actin polymerization mediator, vasodilator-stimulated phosphoprotein (VASP). In diabetes, reduced bioavailability of NO can occur as a result of alterations in growth factor/cytokine receptor balance, downstream signaling, or downregulation of NO synthase (NOS) activation. Reduced NO can alter actin polymerization affecting EPC migration and their ability to carry out endothelial repair. Our hypothesis is that in diabetic individuals reduced NO bioavailability results in decreased EPC migration, attachment and invasion contributing to inadequate endothelial repair and development of acellular capillaries. State-of-the- art imaging, fluorescent activated cell sorter analysis, novel in vitro culture assays and diabetic animal models will be used in combination with biochemical and molecular biological techniques to test our hypothesis. We propose the following specific aims: Specific Aim 1: Our hypothesis predicts that diabetic EPCs will be unable to home to the retina and repopulate acellular capillaries whereas EPCs from normals will. Diabetic mice that have developed acellular retinal capillaries will be injected systemically with EPCs from nondiabetic rodents and the degree of vascular repair examined. Specific Aim 2: Our hypothesis predicts that NO regulates EPC migration .directly by promoting cytoskeletal changes. We will determine which factors regulate EPC NOS isoform expression and NO generation and delineate the NO signaling pathway that regulates cytoskeletal dysfunction in diabetic EPCs. Specific Aim 3: Our hypothesis predicts that diabetic CD34+ EPC cells have defective attachment and invasion. We will determine whether EPC attachment is dependent upon inherent properties of the EPC or the local matrix environment and evaluate human diabetic and nondiabetic CD34+ cell attachment to normal and glycated matrix. The exciting implication of our hypothesis is that early repair of the EPC migratory defect may deter the subsequent development of proliferative diabetic retinopathy.

描述（由申请人提供）：糖尿病视网膜病变（DR）是西方世界工作年龄成年人失明的主要原因。早期周细胞脱落和内皮细胞死亡导致无细胞毛细血管的形成，从而导致视网膜缺氧和缺血，是 DR 发生的重要因素。我们已经证明，健康动物的造血干细胞和内皮前体细胞 (EPC) 很容易归巢到视网膜，但糖尿病动物和人类的 EPC 存在迁移缺陷。我们的初步研究表明，EPC 功能障碍可能为糖尿病视网膜病变中脱细胞毛细血管的发育提供一种新机制。我们的数据表明，在 EPC 内，一氧化氮 (NO) 在调节肌动蛋白聚合介质、血管舒张刺激磷蛋白 (VASP) 方面发挥着关键作用。在糖尿病中，生长因子/细胞因子受体平衡、下游信号传导或一氧化氮合酶 (NOS) 激活下调的改变可能导致一氧化氮生物利用度降低。减少的 NO 可以改变肌动蛋白聚合，影响 EPC 迁移及其进行内皮修复的能力。我们的假设是，在糖尿病个体中，NO 生物利用度降低会导致 EPC 迁移、附着和侵袭减少，从而导致内皮修复和无细胞毛细血管发育不足。最先进的成像、荧光激活细胞分选仪分析、新型体外培养测定和糖尿病动物模型将与生化和分子生物学技术结合使用来检验我们的假设。我们提出以下具体目标：具体目标 1：我们的假设预测，糖尿病患者的 EPC 将无法归巢至视网膜并重新填充无细胞毛细血管，而正常人的 EPC 则可以。已发育出无细胞视网膜毛细血管的糖尿病小鼠将被全身注射来自非糖尿病啮齿动物的 EPC，并检查血管修复程度。具体目标 2：我们的假设预测 NO 通过促进细胞骨架变化直接调节 EPC 迁移。我们将确定哪些因素调节 EPC NOS 亚型表达和 NO 生成，并描绘调节糖尿病 EPC 细胞骨架功能障碍的 NO 信号通路。具体目标 3：我们的假设预测糖尿病 CD34+ EPC 细胞有缺陷的附着和侵袭。我们将确定 EPC 附着是否依赖于 EPC 或局部基质环境的固有特性，并评估人类糖尿病和非糖尿病 CD34+ 细胞与正常和糖化基质的附着。我们的假设令人兴奋的是，EPC 迁移缺陷的早期修复可能会阻止增殖性糖尿病视网膜病变的后续发展。